The present invention is generally related to liquid aerosol generators. In particular, the present invention is related to methods and devices for identifying the contents of a nebule to improve the delivery of the aerosolized liquid to the patient.
The ability to aerosolize or nebulize small liquid droplets is important in a variety of industries. Merely by way of example, many pharmaceuticals can now be delivered to the lungs in liquid droplet form through use of an aerosol generator, such as a nebulizer inhaler. Aerosolization is also a useful technique to dispense deodorizers, perfumes, insecticides, or the like, into the atmosphere or to other target areas.
Aerosol generators can be configured to deliver a number of different pharmaceutical aerosols to the patient's lungs or other target areas of the body. Typically, the aerosol generator will utilize a removable supply of a liquid pharmaceutical that is contained in some type of portable nebule, such as an ampoule, container, canister, reservoir, or the like.
While the existing aerosol generators have proven to be effective, the existing aerosol generators suffer some limitations. One problem with existing aerosol generators is that users may inadvertently install and nebulize an incorrect drug nebule into the aerosol generator. As can be appreciated, delivery of the wrong drug can be extremely dangerous, if not fatal.
Another problem with existing aerosol generators is that the aerosol generator cannot identify the liquid in the nebule. Consequently, it has proven to be difficult to provide an efficient delivery of the aerosolized pharmaceutical to the patient. Since some of the pharmaceuticals to be aerosolized may be more effective when delivered near the beginning of a patient's breathing cycle, while other pharmaceuticals may be more effective when delivered near the end of the patient's breathing cycle it is preferable that the aerosol generator be able to identify the type of liquid disposed in the nebule so that the correct delivery sequence can be chosen to deliver the aerosol to the patient. While the existing nebulizers have proven to be effective within certain parameters, the existing nebulizers also present opportunities for improvements.
One area for improvement is the calculation and control of the precise time of aerosol delivery within a user's or patients breathing cycle. This is especially in issue with respect to patients that receive some of all of their inspiratory air from a ventilator device. Existing nebulizers may deliver a constant flow of aerosol into the ventilator tubing, which can lead to a significant amount of aerosol lingering in the tubing or other elements of the overall ventilator system—this lingering aerosol may not be inhaled, as it collects while the patient is exhaling or otherwise not inhaling, resulting in a significant amount of aerosolized medication being pushed out of the system, such as during exhalation, without being inhaled by the patient. Such situations are problematic for a number or reasons. First, the dosage of drug that actually is inhaled by the patient may be significantly inaccurate because the amount of medication the patient actually receives into the patient's respiratory system may vary with fluctuations of the patient's breathing pattern. Further, a significant amount of drug that is aerosolized may end up being wasted, and certain medications are quite costly, thus health-care costs can be escalated. Further still, unused aerosolized medication will typically be released to the ambient atmosphere with a patent's exhalation. This can end up medicating individuals in the patient's surroundings and this may give rise to adverse effects with respect to such individuals. Moreover, in a hospital environment such individuals may be either health-care providers, who could be exposed to such air pollution over a prolonged period of time, or other patients, who may be in a weakened condition or otherwise overly sensitive to exposure to non-prescribed or excessive amounts of a medication.
For these reasons, it is desired to provide an aerosol generator that can obtain information about the contents of the nebule. In particular, it is desired to provide methods and devices, which can determine the type of liquid disposed in the drug so as to provide an improved level of safety to the patient and an increased efficiency in the delivery of the aerosol to the patient. Further, for these reasons, it is desired to provide methods and devices that can provide aerosol to a patient at a selected interval of the breathing cycle. It is also desired to provide methods and devices that can provide aerosol to a patient at a selected interval wherein the interval is selected based on the identity of the drug to be administered.